A dual-sided harped turnbuckle external post-tensioning (T-EPT) for retrofitting reinforced concrete beams

• Main Authors: Ferrer, Candice Maree N., Lee, Myung Hun, Lopez, Jerson J., Soriano, Reynaldo Timothy C.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Prestressed concrete beams
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/9728
• Institution: De La Salle University

As time progresses, the decrease in structural performance is inevitable for every structure. Its structural members will eventually weaken due to overstressing and environmental factors. Consequently, deflection can occur specifically in RC beams, comprising its strength and serviceability. There are many solutions to this problem one of which is to retrofit the deteriorated structural member. Although another option is to demolish the structure and construct a new one, it is not always economical and practical. As a continuation of the study conducted by Lejano, Grimares, Peñamante, & Roxas (2013) on the turnbuckle type of external post-tensioning (T-EPT), the group established an improved design of the setup in terms of practicality and efficiency. This time, the setup consisted of two M16 turnbuckles that were used to tension the steel cables attached to a smaller steel frame. In addition, the anchorage was adjusted into a horizontal orientation for easier application. Results from the experimental tests demonstrated an increase in the effectiveness of T-EPT specifically in increasing the load capacity of the beam and decreasing the load capacity of the beam and decreasing the deflection. The average increase in load capacity and the average decrease in deflection were 38.65% and 43.18%, respectively. Furthermore, the group was able to determine the jacking force generated from the T-EPT on each beam, which ranged from 29 to 32 kN. The results showed consistency with a previous research entitled Fiber Method Analysis of RC Beam Retrofitted with Turnbuckle External Post-Tensioning (Lejano, 2016), wherein there would already be significant improvement in the RC beam even with minimal amount of jacking force.